This application is based on Application No. 2001-239562, filed in Japan on Aug. 7, 2001, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a capacitor assembly for an alternator providing a capacitor component in an interior space of an alternator case, and to a method for the manufacture thereof.
2. Description of the Related Art
Conventionally, in alternators, a capacitor component is connected in parallel between a positive electrode and a negative electrode of the alternator, being constructed mainly to absorb surges generated by a rectifier assembly and to prevent the propagation of noise to vehicle electrical load devices such as audio systems.
The capacitor component is accommodated inside a cup-shaped capacitor receptacle, being integrated with the capacitor receptacle by a filler resin injected inside the capacitor receptacle and hardened. The capacitor assembly is constructed by inserting the capacitor receptacle containing the capacitor component into an insertion aperture disposed through a brush holder which is a rear-end built-in molded part, and joining component terminals to holder terminals by a joining means such as soldering.
In the conventional capacitor assembly constructed in this manner, because the capacitor receptacle containing the capacitor component is supported in the brush holder by means of the joint portions between the component terminals and the holder terminals, the joint portions between the component terminals and the holder terminals bear the weight of the capacitor receptacle, the capacitor component, and the filler resin. When the alternator is mounted to the engine of an automobile, vibrations from the engine are transmitted to the alternator when the engine is running. Thus, the weight of the capacitor receptacle, the capacitor component, and the filler resin becomes a vibrating load acting repeatedly on the joint portions between the component terminals and the holder terminals, and one problem has been the occurrence of dislodging of the joint portions.
In order to solve problems of this kind, capacitor assemblies have been proposed as improvements in Japanese Patent Laid-Open No. 2000-209824 and Japanese Patent Laid-Open No. 2001-16829, for example, in which the weight of the capacitor receptacle, the capacitor component, and the filler resin is prevented from acting on the joint portions between the component terminals and the holder terminals by forming the brush holder and the capacitor receptacle into an integrated body.
In these capacitor assemblies proposed as improvements, as shown in FIGS. 19 and 20, a cup-shaped capacitor accommodating portion 71 is formed in a portion of a brush holder 70 when the brush holder 70 is formed by molding using a polyphenylene sulfide (PPS) resin. The capacitor component 35 is accommodated in the capacitor accommodating portion 71, a filler resin 73 composed of an epoxy resin is injected into the capacitor accommodating portion 71 and hardened, and then component terminals 74 are soldered to holder terminals 75.
Thus, the brush holder 70 (the capacitor accommodating portion 71) bears the weight of the capacitor component 35 and the filler resin 73. Hence, the weight of the capacitor component 35 and the filler resin 73 is prevented from becoming a vibrating load acting repeatedly on the joint portions 76 between the component terminals 74 and the holder terminals 75, thereby preventing the occurrence of dislodging of the joint portions 76.
In the conventional capacitor assemblies proposed as improvements, as explained above, a PPS resin and an epoxy resin are used in a resin portion 72 of the brush holder 70 and for the filler resin 73, respectively.
Thus, because the resin portion 72 of the brush holder 70 and the filler resin 73 have differing coefficients of thermal expansion and thermal contraction, one problem has been that the interface between the resin portion 72 and the filler resin 73 separates due to ambient temperature increases or heat received from other heat-generating parts, and salt water, etc., may penetrate the gaps therebetween, giving rise to insulation failure.
Furthermore, in order to secure the capacitor component 35, the capacitor accommodating portion 71 is filled with the filler resin 73, requiring a process for hardening the filler resin 73, and thus another problem has been that manufacturing time is lengthy.
The present invention aims to solve the above problems and an object of the present invention is to provide a capacitor assembly for an alternator and a method for the manufacture thereof enabling suppression of insulation failure due to penetration by salt water, etc., by molding a capacitor component integrally during molding of resin-molded parts to be mounted to the alternator to prevent separation resulting from ambient temperature increases or heat received from other heat-generating parts, and also enabling manufacturing time to be shortened by omitting processes for filling and hardening a filler resin.
With the above object in view, a capacitor assembly for an alternator of the present invention includes a resin-molded part formed by molding using a first molding resin, a positive terminal and a negative terminal insert molded into the resin-molded part, and a capacitor component installed between a battery terminal end and ground. The resin-molded part is mounted to an alternator case. The capacitor component has a capacitor positive electrode terminal and a capacitor negative electrode terminal for electrical connection to the positive terminal and the negative terminal. The capacitor component is molded integrally into the resin-molded part so as to be embedded in the resin-molded part.
Therefore, there is provided a capacitor assembly for an alternator enabling suppression of insulation failure due to penetration by salt water, etc., by preventing separation resulting from ambient temperature increases or heat received from other heat-generating parts, and also enabling manufacturing time to be shortened by omitting processes for filling and hardening a filler resin to secure the capacitor component.
With the above object in view, a method for manufacturing a capacitor assembly for an alternator of the present invention includes the step of molding a positive terminal, a negative terminal, and a capacitor component using a first molding resin to integrally mold The capacitor component has a capacitor positive electrode terminal and a capacitor negative electrode terminal for electrical connection to the positive terminal and the negative terminal. The capacitor component is installed between a battery terminal end and ground.
Therefore, there is provided a method for manufacturing a capacitor assembly for an alternator enabling suppression of insulation failure due to penetration by salt water, etc., by preventing separation resulting from ambient temperature increases or heat received from other heat-generating parts, and also enabling manufacturing time to be shortened by omitting processes for filling and hardening a filler resin to secure the capacitor component.